boxgrinder/boxgrinder-build — comment on commit 251e31d2fa8f4ad4aa46db5f48d4be983feed4f4
File: Rakefile line 34
By goldmann:

You're right I missed that somehow. But this doesn't solve the problem.

The thing is that ruby-libvirt is not shipped as a gem in Fedora, it's a normal package with Ruby extension written in C. When you require is at as gem - it fails at runtime (Fedora 16) with message that we don't have such gem installed.

Take a look at the content of ruby-libvirt and everything will be clear.